Bio-Inspired Pangolin Design for Self-Healable Flexible Perovskite Light-Emitting Diodes

Abstract

Despite tremendous developments in the luminescene performance of perovskite light-emitting diodes (PeLEDs), the brittle nature of perovskite crystals and their poor crystallinity on flexible substrates inevitably lead to inferior performance. Inspired by pangolins' combination of rigid scales and soft flesh, we propose a bionic structure design for self-healing flexible PeLEDs by employing a polymerassisted crystal regulation method with a soft elastomer of diphenylmethane diisocyanate polyurethane (MDI-PU). The crystallinity and flexural strain resistance of such perovskite films on plastics with silver-nanowire-based flexible transparent electrodes are highly enhanced. The detrimental cracks induced during repeated deformation can be effectively self-healed under heat treatment via intramolecular/intermolecular hydrogen bonds with MDI-PU. Upon collective optimization of the perovskite films and device architecture, the blue-emitting flexible PeLEDs can achieve a record external quantum efficiency of 13.5% and high resistance to flexural strain, which retain 87.8 and 80.7% of their initial efficiency after repeated bending and twisting operations of 2000 cycles, respectively.

Flexible perovskite light-emitting diodes for display applications and beyond

“…The mechanical stability and stretchability of perovskite films can be strengthened by incorporating PEO, where the perovskite crystals are embedded into PEO matrix [36,37,44,134] .…”

Recent Progress in Self-Healable Hydrogel-Based Electroluminescent Devices: A Comprehensive Review

“…Such inspirations help us to develop today’s electroluminescence technology by integrating model concepts into the design. Qian, X. et al [ 46 ] developed self-healing flexible perovskite light-emitting diodes (PeLEDs) from a biologically inspired pangolin design. Developed PeLEDs have shown better bending strength.…”

Cross-linking polymerization boosts the performance of perovskite solar cells: from material design to performance regulation

“…143,144 For example, under mechanical stress, some cracks may appear in the perovskite film and the hydrogen bonds in the polymer chains are broken. 145 After heat treatment, the dynamic hydrogen bonds can be reconstructed to repair cracks on a macroscopic scale, which can lower the performance loss arising from non-radiative recombination (Fig. 11a).…”